A wireless access network, like a wireless local access network (WLAN), may be accessed by a mobile device for making use of services provided by the wireless access network. Some wireless access networks may provide an unlimited access. Other wireless access networks may request an authentication of a mobile device before enabling an access, for instance in order to be able to charge for a provided service. Still other wireless access networks may provide an access only to mobile devices of a selected group. A service that may be provided by a wireless access network, among others, is a connection to the Internet or to some other network.
Some mobile devices comprise a “search for WLAN” functionality, which allows a user to connect to any available WLAN without having a preconfigured profile. In mobile terminals Nokia 9500 and 9300i, for instance, this functionality is called Easy WLAN. Some devices might also implement this functionality implicitly and join to previously unknown networks automatically, if none of the preconfigured networks are available.
When a user selects the “Search for WLAN” functionality or when such functionality is used automatically, and the mobile device discovers a WLAN which is not known to the mobile device so far, however, the mobile device may still lack important information.
For instance, the mobile device does not know the connectivity that is provided by the new connection. A user may desire to connect to the global Internet making use of the WLAN, but the WLAN might provide, for instance, only a limited Internet access or only an access to an enterprise intranet.
Further, in many public WLANs, the user has to perform a browser authentication in order to get access to the network. This is sometimes referred to as the Universal Access Method (UAM). The user may enter some Uniform Resource Locator (URL), and a browser sends a Hypertext Transfer Protocol (HTTP) requests to the WLAN. An access controller of the WLAN intercepts, or hi-jacks, the HTTP session and presents a login page to the user. The user logs on by filling in the fields on the login page.
When such a browser authentication is used, the mobile device does not know when the user has successfully completed the browser authentication. As a result, the middleware of the mobile device is not able to indicate the availability of the new connection to the application, to a Mobile Internet Protocol (IP) client or to a virtual private network (VPN) client requesting the access at the correct time. If the new connection is indicated to be available before the authentication phase has been completed, then the connectivity of the application, the mobile IP or the VPN client will be unnecessarily meddled, possibly leading to a connection failure.
Further, after joining a new WLAN, the mobile device does not know yet whether or not browser authentication is required. This makes it difficult to decide whether to save the connection for future use. It might not be desirable to save the connection for future use, if the authentication information is missing.
Further, when the user is using the browser, the mobile device does not know whether the user is just generally browsing or performing browser authentication to a WLAN. Therefore, the mobile device is not able to help the user with the browser authentication, for example by “recording” the browser authentication as a script and playing it back on the next connection.
Mobile devices that support several network access technologies may moreover use different connection methods to connect to a destination or target network, like the public Internet, a private network such as an enterprise intranet or an operator service network. A mobile device may reach the Internet, for instance, via a WCDMA network or via some WLAN. When establishing a connection to a particular destination network, the mobile device could automatically select the best available connection method. Once a connection to the destination network has been established, the mobile device could further roam automatically between the connection methods to ensure that always the best available connection method is used. Such a roaming can be performed on an application-level or on a network-level. For an application-level roaming, the mobile device does not require support from the network. A network-level roaming, in contrast, requires some network support.
Usually, it only makes sense to roam automatically between connections that connect to the same destination network, like the Internet. When discovering a WLAN, which is unknown to the mobile device, with the “Search for WLAN” functionality, the mobile device does not know the connectivity provided by the new connection. Therefore, the connection cannot easily be used for roaming. The roaming decision is also rendered difficult, since the mobile device does not know whether browser authentication is required when joining a new WLAN.